DD287690A5 - ARRANGEMENT FOR DETECTING MOVEMENT SIZES OF VEHICLE TRAILERS - Google Patents

Abstract

The invention relates to an arrangement for determining selected Bewegungsgroeszen of vehicle wheels, wherein the Bewegungsgroesze erfazzt with a transmitter and is used to determine control signals to influence the braking process by an ABS. The invention is characterized in that the output of the downstream sequencer pulse shaping stage is connected to the STB input of the memory latch, the data inputs of the memory latch being coupled to the outputs of a binary counter clocked by the generator. Fig. 1 {Anti-lock Braking System; Vehicle wheels; Giver; Bewegungsgroesze; pulse shaper; Control signal; binary counter; memory latch; Generator; Data input; count register}

Description

embodiment

The invention will be explained with reference to an embodiment näner. Show

1 shows a functional diagram of the arrangement according to the invention

Fig. 2: timing diagram and counting scheme

3 shows a block diagram of a concept for a single-chip microcomputer.

1, a pulse train is obtained by means of a pulse disc 1, a Meßgrößenaufnehmer 2 and a pulse shaper 3, the frequency fi of the wheel speed is proportional. 2, the duration of a measurement cycle is defined by the sum of a constant, fixed line T ₁ and a variable residual time ΔΤ (time after the expiration of T, until the arrival of the next pulse of frequency fi).

1, a binary counter 6 runs continuously at the clock frequency fj of a generator 7. In this case, f ₂ *> f _t . The H / L edges of the pulses of the frequency f _t initialize via the SI d input the writing of the respective count of the binary counter 6 in the memory latch 5. According to Figure 3 it is assumed that the count register 4, the memory latch 5 and the generator Components of a Einchipmikrorechners 8 are. The tasks of the single-chip computer 8 are shown in FIG. 2. The counter reading Z ( _Mt at the time to is read-stored and, according to the fixed constant time T, a target counter reading is obtained

Zfvor ⁼ Zf.t + T ₁ · fj

calculated. Taking into account a counter overflow corresponding to Fig.2 Il (III)

Zfvor = Zhi - Z ( _ml "+ T, · f j.

If, according to Fig. 21, Z _r ,> ZfV ₀₁ , then Zfiki ^β Zn - Zf, _t .

If, according to FIG. 2, a counter overflow took place between Z _FII _ _υ and Z _n , or if after a counter overflow corresponding to FIG. 2 III 2 _r , Z ^ ₀₁₁ then applies

Zfjki = Z ( _mu - Zf.t + Z (J.

The measuring cycles follow according to Fig. 21 without Zwischenrcum directly on each other. At the end of each measuring cycle, the reference pulse quantity Z | _old and in the counting register 4, the pulse quantity Z ₂ , available. From them can the angular velocity in the form

ω = const * Zi / Zfakt

be calculated. In the ROM 9 of the single-chip computer 8, corresponding to FIG. 3, a correction function Zn is stored. From i ^ n a ROM address is formed and the value Ζλ, μ fetched from the ROM table. Thus, the product of Z ₁ and Z _fti ki is a measure of the average angular velocity in the current measurement cycle.

The measured variables can be processed in the single-chip computer 8 to "ABS-reievanten" switching variables for engagement in the brake system.In an output latch 10 are the corresponding signals for the power electronics 11 of the actuators ready.

Claims (3)

1. Arrangement for determining movement quantities of vehicle wheels with a Meßgrößenaufnehmer and a Impulsformerstufe which outputs a frequency proportional to the wheel speed, a count register, a generator which emits pulses of a high constant frequency and a microcomputer, characterized in that the output of the Impulsformerstufe with downstream of the memory latch, the data inputs of the memory latch being coupled to the outputs of a binary counter clocked by the generator. 2. Arrangement according to claim 1, characterized in that the counting register, the memory latch and the generator for the frequency f ₂ fancy as Einchiprechner * is. For this 3 pages drawings Field of application of the invention The invention relates to an arrangement for determining selected quantities of motion of vehicle wheels, in which the amount of movement detected by a transmitter and used to determine steering signals to influence the braking process by an ABS. Characteristic of the known technical solutions It is known from DE-OS 2329714 a device for blocking-preventing control of the deceleration of a vehicle, in which a signal is formed by the counting of pulses of a wheel speed proportional frequency within a predetermined period of time. Disadvantage of this measurement method is the limited number of pulses per wheel revolution, which requires large measurement times to realize the necessary for anti-lock system high signal resolution. It is also known from OE-OS 2844 279 a device for blocking-preventing control of the deceleration of a vehicle, in which the time duration between successive edges of the wheel speed porportionaler pulses is counted. The reference quantity of the measurement is therefore a constant angle. The disadvantage of the method is that the time for the measurement increases greatly with decreasing wheel speed and that increases with increasing wheel speed, the relative error, for example due to existing pitch inaccuracies. Furthermore, a method is known from DD-PS 236289, which avoids the disadvantages of the above-mentioned method and realizes a high signal resolution at a nearly constant measuring time over the entire speed range. A disadvantage of this method is the increased hardware complexity for the switching of counting frequencies, the Vorvor specific components of certain microcomputer families, for example, programmable counter-timer, and the N. -Useful power interrupt systems in the microcomputer target of the invention The aim of the invention is to determine motion quantities of vehicle wheels of a motor vehicle equipped with an ABS, wherein the arrangement has a minimal hardware expenditure with high signal resolution and achieves a constant over the entire speed range small measurement time. An angular velocity-proportional variable for determining "ABS-relevant" switching thresholds is provided by a computer without time-consuming arithmetic operations. Explanation of the essence of the invention The object of the invention is to provide an arrangement for the realization of the aforementioned method, which avoids the disadvantages of known technical solutions. It is linked to the important for anti-lock brakes high signal resolution at a nearly constant small measurement time with minimal hardware cost. The hardware is not tied to a specific microcomputer family, but has only common structures present in each family of computers. According to the invention, this object is achieved in that the Auüg-ang pulse shaper stage is connected with downstream counting register to the STB input of the memory latch, wherein the data inputs of the memory latch with the outputs of a binary counter, which is clocked by the generator gekoppe '. The counting register, the memory latch and the generator for the frequency I ₂ are formed as a single-chip computer. The wheel sensor pulses are summed from a start pulse within a predetermined time. After this time, a reference pulse amount is formed, which represents the time between the start pulse and the next incoming sensor pulse. For this purpose, with each pulse of the wheel sensors registering the count of a binary counter, which is clocked by the pulses of a high constant frequency, initiated in a memory latch. The number of sensor pulses and the reference pulse quantity can be detected very quickly by means of a microcomputer. Thus, there remains sufficient time for the further processing with regard to "ABS-relevantor" parameters which allow influencing the braking process.